Manchester United’s Sir Alex Ferguson has backed Real Madrid and former Chelsea boss Jose Mourinho to be his replacement once the evergreen 70-year-old pulls the pin at Old Trafford.

Ferguson, who’s been in the Man U dugout for 25 years, was speaking to ITV4 ahead of a documentary, Mourinho, airing tonight at 10pm.

"He can manage anywhere, absolutely,” Fergie says. “I'm not going to put any forecasts on what is going to happen at this club. I won't last forever, but Jose can manage anywhere, there is no question about that."

Mourinho forging such a formidable career as a manager without any notable playing credentials, Ferguson says, makes the Portugese’s 21 trophies in 10 years as a coach even more “incredible”.

Fergie said he thought Mourinho was “cocky” when he referred to himself as the “special one” when he got to Chelsea, but rated his confidence.

"I would never think a guy who hasn't played a game could be a top coach, but then you've got to look at his personality, I think his personality does it," Ferguson says.

"He's got a marvellous, strong personality and I think that bridges that gap.

"How old is he now? Fiftieth year. So he is 20 years behind me. At the same rate he is going to add another 42 trophies. At the current rate, (that is) amazing isn't it?"

Ferguson said earlier this year that he would retire in “another two or three years”, but insiders have also said he’ll continue as long as he’s healthy. He turns 71 on New Year’s Eve.